Liquid container and method of manufacturing same

ABSTRACT

A liquid container comprises a flexible bag-shaped container body 1 which is provided with two flat portions 3(3a,3b) as front and back walls and two gusset portions 4(4a,4b) as side walls which are folded inwardly, and a pipe-shaped delivery unit 2 which is provided with a mouth portion 11 at an upper end thereof to be projected out of an upper end portion of the container body, and a flange portion 12 below the mouth portion to be held at a joining portion 5 of the upper end portion of the container body, wherein each gusset portion 4 has a width approximately equal to that of the flat portion 3, inward end portions 15(15a,15b) of the two gusset portions being interposed between the flange portion 12 and the flat portion 3 at the joining portion 5. When the liquid container is manufactured, it is preferable that films for the gusset portions are temporarily bonded to a film for the flat portion before the positioning of the delivery unit.

FIELD OF THE INVENTION

The present invention relates to a liquid container to be filled witheatable or uneatable liquids or fluids, for example beverages such assportsdrink and orange juice, and relates to a method of manufacturingthe liquid container.

BACKGROUND OF THE INVENTION

There has been known a container for filling beverages such assportsdrink and orange juice. The container has a bag-shaped containerbody formed of a flexible film as forming material and having gussetportion; and a pipe-shaped delivery unit joined to the container body ina state that its flange portion is held at an end portion of an upperopening of the container body. The conduit portion of the delivery unitis inserted into the container body. It is disclosed in, for example,Japanese Utility Model Application Laid-Open(Kokai) No. 62-134826, whichis laid open to the public in 1987.

Such kind of the liquid container is lighter in its weight and can beopened more easily than cans and bottles. Therefore, it can be used as acontainer to store beverages and sauces for Japanese noodles orKorean-style barbecued meat instead of glass bottles and plasticcontainers.

The above liquid container is, as shown in FIGS. 13 and 14, constitutedof a bag-shaped container body 1 having two gusset portions 4(4a,4b)folded inwardly and two flat portions 3(3a,3b), and a delivery unit 2having a flange portion 12 and a conduit portion 13. The gusset portions4a, 4b folded inwardly are respectively positioned on both sides of thebody 1 so that they make a space S1, where the flange portion 12 of thedelivery unit 2 is set, between both inward ends 15a, 15b at the upperend portion of the container body 1. Thus, the upper end portion and theflange portion 12 are integrally bonded to each other by means of anusual heat sealing. The liquid container formed in such a manner hasgaps S2 which are made between the flange portion 12 and each inward end15a, 15b of the gusset portions.

In the above liquid container, however, the fact that the flange portion12 of the delivery unit 2 is set in the space S1 between both inwardends 15a, 15b of the gusset portions results in that a horizontalsection of the container body 1 is made rectangular and never regularlysquare, because whole size in width of the gusset portion 4 is narrowerthan that of the flat portion 3. Therefore, the liquid container is notstable in self-standing and frequently topples down when it is put on ashelf or the rack for displaying.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a liquid containerwhich has a high stability in self-standing when it is put on a shelf orrack. It is another object of the present invention to provide apreferable manufacturing method for the above liquid container.

In order to achieve the above objects, a liquid container of the presentinvention comprises: a bag-shaped container body formed of a flexiblefilm and composed of two flat portions which constitute front and backwalls and two gusset portions which are folded inwardly to constituteside walls; and

a pipe-shaped delivery unit having at least a mouth portion which isformed at an upper end thereof and projects out of an upper end portionof the container body, and a flange portion which is formed below themouth portion and held at the upper end portion of the container body toconstitute a joining portion between the delivery unit and the containerbody,

wherein, each of the gusset portions has a width approximately equal tothat of the flat portion, each inward end portions, projected inwardly,of the two gusset portions being positioned between the flange portionand the flat portion at the joining portion.

Further, a manufacturing method for the above liquid container comprisessteps of:

preparing two flexible films to be flat portions constituting front andback walls of the container body, other two flexible films each having awidth approximately equal to that of the film for the flat portion andbeing to be gusset portion constituting a side wall of the containerbody, and a pipe-shaped delivery unit having at least a mouth portionformed at an upper end thereof and a flange portion formed below themouth portion;

superposing the two films for the flat portions onto each other;

folding and positioning the two films for the gusset portions betweenthe superposed two films for the flat portions in a state that both endportions, in which folding lines are formed, face oppositely in a mannerof contacting or coming close to each other;

positioning the delivery unit between the superposed two films for theflat portions in a state that the mouth portion of the delivery unitprojects out of an upper end portion of the container body and theflange portion of the delivery unit is set to the upper end portion ofthe container body; and

bonding integrally the respective films for the flat or the gussetportions and the delivery unit by sealing predetermined portionsthereof,

wherein each of the films for the gusset portions is temporarily bondedto the film for the flat portion before positioning the delivery unit,and

each end portion, in which folding lines is formed, of both the filmsfor the gusset portion is interposed between the flange portion of thedelivery unit and an upper end portion of the film for the flatportions.

According to the above liquid container, the flange portion of thedelivery unit is positioned and held at the upper end portion of thecontainer body to form the joining portion in a state that the flangeportion overlaps with the inward end portions of the gusset portions.Therefore, each gusset portion is folded deeply to shape a cross sectionof the container body into an approximately regular square, so that thestability in self-standing is ensured when the liquid container is puton a shelf or rack for displaying.

In the above liquid container, it is preferable that both inward endportions of the gusset portions are disposed on the same side withrespect to the flange portion. According to this preferable embodiment,the pipe-shaped delivery unit slants inevitably to a front or backdirection of the liquid container, so that an user can put his lipeasily on the mouth of the delivery unit to drink the content.Furthermore, indications or letters on the flat portion can be viewed byconsumers to improve an effect of the eye-catching if the top of thedelivery unit slants to the rear side to direct upwardly the upperportion of the front flat portion even when the liquid container is puton a considerably low shelf.

Oblique seal lines may be formed at four lower corner portions of thecontainer body so as to extend obliquely across the flat portions fromone side edge to the bottom edge thereof, and subsequently an outerportion beyond each oblique seal line and the bottom seal line maybe cutoff. According to this embodiment, a resistance of the container bodyagainst the folding of the bottom edge portion is reduced, so that thebottom portion is flattened easily and the stability in self-standing ofthe liquid container is improved.

In another preferable embodiment of the above liquid container, thewidth of top seal lines of the container body which extend from thejoining portion to the left and right sides thereof may be formed largerthan that of the sealed joining portion, and an edge line of eachtransitive portion between a lower corner of the joining portion and alower inner edge of the top seal line may be extended substantiallyparallel to an axis of the container body. According to this embodiment,the strength of the gusset portions is increased by the enlarged topseal lines in their widths. Furthermore, since each transitive portionbetween the lower corner of the joining portion and the lower inner edgeof the top seal line is extended substantially parallel to an axis ofthe container body, a pressure of the content in the liquid containerwhich concentrates on the lower corners of the joining portion isdecreased to improve the strength of this portion and to preventpinholes and breakages of the liquid container.

On the other hand, according to the above manufacturing method, it iseasy to conduct the positioning of the films for the flat and gussetportions. Simultaneously, the delivery unit and the films for any partsof the container body can be sealed under a stable condition by thetemporarily bonding of the films for the gusset portions.

It is preferable to constitute the above manufacturing method so thatthe two films for the gusset portions are put on the predeterminedpositions of the film for the flat portion, and subsequently they aretemporarily bonded to the film for the flat portion by heat sealing inwhich a seal bar is pressed onto the films so as to cross over thefolding lines of the films for the gusset portions at an upper portionof the container body. According to this embodiment, a productivity ofthe liquid containers is increased and generation of the defectives isdecreased, because the inward end portions of the gusset portions do notcollide with the delivery unit during the positioning thereof onto thegusset portions, and do not disturb the positioning of the deliveryunit.

In the case where such a temporary bonding is conducted in the abovepreferable manner with the seal bar, the seal bar may have a sealingsurface which comprises a triangle recess at its center portion on oneside thereof, each edge of the recess crossing obliquely over thefolding lines of the films for the gusset portions so that a sealingarea is enlarged toward a direction of a side portion of the containerbody. Thus the strength of the liquid container against the variousimpacts, such as an impact when the container drops down, can beincreased by a specific sealing area of the temporary bonding whichcorresponds to the above sealing surface of the seal bar.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a front view showing an embodiment of the liquid containeraccording to the present invention.

FIG. 2 is a perspective view of the liquid container showing a statethat it is inflated according to the present invention shown in FIG. 1.

FIG. 3 is a front view showing a delivery unit of the liquid containeraccording to the present invention shown in FIG. 1.

FIG. 4 is an explanatory view showing an inner constitution of theliquid container according to the present invention shown in FIG. 1.

FIGS. 5A and 5B are cross-sectional views schematically showing twoembodiments of the joining portion for the delivery unit.

FIGS. 6A and 6B are views of another embodiment of the liquid containeraccording to the present invention showing a state that it is inflated,in which FIG. 6A is a perspective view and FIG. 6B is a side view.

FIGS. 7A and 7B are views showing a bottom portion of the liquidcontainer according to the present invention shown in FIG. 1.

FIG. 8 is a view showing an upper portion of the liquid containeraccording to the present invention shown in FIG. 1.

FIG. 9 is a view showing a constitution of an embodiment of films toform the container body.

FIG. 10 is a flow diagram showing an embodiment of a manufacturingmethod according to the present invention.

FIG. 11 is a view showing an embodiment of the temporary bonding.

FIG. 12 is another view showing the temporary bonding shown in FIG.11.

FIG. 13 is a perspective view showing a conventional liquid container.

FIG. 14 is a cross-sectional view taken along the lines A--A of FIG. 13and schematically shown.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will be explainedhereunder with reference to the accompanying drawings.

FIG. 1 is a front view showing a liquid container 101 which is oneembodiment of the liquid container according to the present invention,FIG. 2 is the perspective view showing the liquid container 101 in aninflating state, and FIG. 3 is a front view showing a delivery unit.Referring to these figures, the liquid container 101 is constituted of abag-shaped container body 1 formed of flexible film and a pipe-shapeddelivery unit 2 usually formed of plastics. The container body 1 isprovided with the joining portion 5 at the upper end portion of the body1, and thus the flange portion 12 of the delivery unit 2 is bonded tothe inner surface of the joining portion 5 of the container body 1. Thecontainer body 1 is composed of the two flat portions 3(3a,3b) whichconstitute front and back walls and the two gusset portions 4(4a,4b)which are folded inwardly to constitute the side walls of the body 1.The body 1 is provided with the respective seal lines which are formedat the peripheries thereof and include top seal lines 6 extending to theright and left of the joining portion 5, side seal lines 7, a bottomseal line 8 and oblique seal lines 9. These seal lines are usuallyformed by means of heat sealing.

The delivery unit 2 has a long and pipe-like shape, which is providedwith at least a mouth portion 11 formed at the upper end thereof, and aflange portion 12 formed below the mouth portion 11 to join the deliveryunit 2 and the container body 1 with each other. Furthermore, the unit 2may be provided with other parts, for example, a conduit portion 13which is formed below the flange portion 12 to improve the function as astraw, a screw portion 14b at the mouth portion to tighten a cap 14a, asupporting flange portion 14c to support the delivery unit on a guidefor guiding only delivery unit or the liquid container with the deliveryunit, and a hole portion 14d to be a path for the purpose of drainingair at the filling time and draining the content in a manner that theliquid container is turned upside down.

FIG. 4 shows a state that the front flat portion 3a is eliminated fromthe liquid container 101. That is, the delivery unit 2 is disposed atthe center of back flat portion 3b, and both gusset portions 4a, 4b aredisposed on both sides thereof. As can been understood from FIGS. 2 and4, the conduit portion 13 of the delivery unit 2 extends inwardly of thecontainer body 1, so that the delivery unit 2 serves as a straw. In thepresent invention, the inward end portions 15 (the folding lines) aredisposed at deep positions close to the center of the container body,because it is necessary to make a whole width W1 of each gusset portionapproximately equal to that W2 of the flat portion for the purpose ofimproving stability in self-standing. Thus, the two inward end portions15a, 15bfaces oppositely with coming close to each other from the bothsides of the container body or contacting mutually at the center of thecontainer body in some cases. At this time, a whole area or a partialarea of the flange portion 12 is covered with the respective inward endportions 15.

Therefore, in the liquid container of the present invention, as can beenseen in FIG. 5 schematically showing the sectional view of the joiningportion 5, the surfaces 16(16a,16b) of the flange portion and innersurface 17(17a,17b) of the flat portion corresponding to the joiningportion are fastened mutually through the inward end portions15(15a,15b) of the folded gusset portions. FIG. 5A illustrates a type ofthe above liquid container 101 in which both the two inward end portions15a, 15bof the gusset portions are disposed on the front surface 16a ofthe flange portion. On the other hand, FIG. 5B illustrates another typein which the inward end portion 15a of the right gusset portion 4a isdisposed on the front surface 16a of the flange portion, and the inwardend portion 15b of the left gusset portion 4b is disposed on the backsurface 16b thereof.

In any case of the above two types, the shape of the sectional view ofthe liquid container becomes approximately regular square when theliquid container has been filled up to improve the ability inself-standing thereof. The type of FIG. 5A is, however, preferablerather than that of FIG. 5B. In a case where the right and left inwardend portions of the gusset portions are disposed on the same side (thefront or the back side) of the flange portion, the long delivery unitslants in the direction opposite to the side of disposition of theinward end portions of the gusset portions with respect to the flangeportion as shown in FIGS. 6A and 6B. Therefore, it is convenient to beutilized as the straw. Because, an user can easily insert the upperopening end of the delivery unit into his mouth in a state wherein hekeeps the container upright without slanting the container. Furthermore,the indications, e.g. letters or pictures, printed on the flat portionsare emphasized to improve the eye-catching effect. That is, in a case ofFIGS. 6A and 6B, the delivery unit 2 is obliqued backwardly to directthe shoulder portion of the front surface of the front flat portion 3a.Therefore, even if the container is put on a relatively low shelf orrack, a consumer can see clearly the indications on the front flatportion.

There are four lower corner portions at the bottom side of the containerbody, that is, the front-right, the front-left, the back-right, and theback-left corner portions. As shown in FIGS. 7A and 7B, the oblique seallines 9 may be formed at the respective lower corner portions as if saidlower corner portions were cut off obliquely by the oblique seal lines9, and subsequently a portion 18 outer than the oblique seal lines 9 anda bottom seal line 8 may be cut off from the container body 1. Accordingto this embodiment in which the bottom portion is formed into a reversedtrapezoidal shape, since the bottom portion is flattened easily when theliquid container is put on the table, it has a high ability inself-standing. The oblique seal lines 9 are formed so as to extend froma predetermined point on the side edges of the flat portions to anotherpredetermined point on the lower edge thereof, passing through aposition 19 where the folding lines formed in the inward end portions 15of the gusset portions cross over the bottom seal lines 8. An angle 23between the oblique seal line 9 and the bottom seal line 8 is usuallyset at approximately 45 degrees.

In the liquid container according to the present invention, since thetop seal lines 6 where the front and the back flat portions are sealedtogether by the medium of the gusset portions are apt to break easily ascompared with other seal lines and other portions, it is preferable thatthe width W4 of the top seal lines 6 is enlarged, as shown in FIG. 8,than that W3 of the seal line forming the joining portion 5 to increasethe strength of the top seal lines 6. If, in this case, the edge line ofeach transitive portion 22 between the lower corner 20 of the joiningportion 5 and the lower edge 21 of the top seal line 6 is extendedsubstantially parallel to the axis of the container body, the pressure Pof the content in the liquid container does not concentrate on the lowercorners 20 of the joining portion 5, and consequently the liquidcontainer is prevented from generation of pinholes and breakages at thelower corners 20 thereof. Therefore, stable quality of the seal portionis ensured at the upper end portion including the joining portion 5 andthe top seal lines 6 of the container body 1.

As to the flexible films for the flat and gusset portions of thecontainer body, for example, the composite film 29 as shown in FIG. 9 isutilized to ensure flexibility of the container body. The composite film29 is composed by laminating a polyester film 25 to be the outermostlayer, a film 26 having a barrier property, a film 27 selected from thegroup consisting of polyester films or oriented nylon films, and apolyethylene film 28 to be the innermost layer in this order. Moreconcretely, the composite films listed hereinafter are preferablyutilized.

(1) OPET(12 μm)/Al(9 μm)/ON(15 μm)/PE(60-120 μm)

(2) OPET(12 μm)/Al(9 μm)/OPET(12 μm)/PE(60-120 μm)

(3) OPET(12 μm)/EVOH(9 μm)/OPET(12 μm)/PE(60-120 μm)

The meanings of the above abbreviations are as follow and the bracketsare the thickness of the films:

"OPET"; The oriented polyethylene-terephthalate film

"Al"; The aluminum foil

"ON"; The oriented nylon film

"PE"; The polyethylene film

"EVOH"; The ethylene/vinyl alcohol copolymer film

Next, the manufacturing method for the above mentioned liquid containerwill be explained. There is described hereunder regarding the case wherethe liquid containers are manufactured one by one, but that method canbe adapted to continuously manufacturing a plurality of liquidcontainers. FIG. 10 shows generous operations of one example of themanufacturing method.

At the beginning, the flexible film is cut into predetermined dimensionsto prepare two films to be the flat portions of the container body andtwo films to be the gusset portions having a width equal to that of theflat portion. The pipe-shaped delivery unit is also prepared at the sametime.

After the preparing, two films for the flat portions are superposed ontoand positioned to each other. The films for the gusset portions arefolded back to form the folding lines extending in the longitudinaldirection thereof, and subsequently a pair of the folded films for thegusset portions are set between two superposed films for the flatportions so that the outer edges of the films for the gusset portionsare positioned at the outer edges of the films for the flat portions andso that a pair of inward end portions which are projected inwardly andfaces oppositely are brought into contact with or close to each other.

After the above positioning, a pair of films for the gusset portions aretemporarily bonded to the film for the flat portion by heat sealing atthe predetermined positions on the films. The heat sealing is conducted,for example, for one second at 250° C. The temporary bonding stabilizesthe positions of the respective films and the delivery unit at the timeof the seal work. The side seal lines of the liquid container may beformed on demand before the temporary bonding.

As shown in FIG. 11, the temporary bonding is usually conducted at theposition which will be the upper portion of the container body. When thetemporarily bonding is conducted, it is preferable that the heat sealingis carried out while pressing the seal bar onto the flat portion so asto cross over the folding lines of the inward end portions 15, so thatboth inward end portions 15 of the gusset portions 4 are bonded to oneof films for the flat portions. According to this manner, the films forany parts and the delivery unit are positioned easily, because theinward end portions 15 of the gusset portions do not collide with thedelivery unit when the delivery unit is put near the gusset portion 4.In particular, in case that the container body is formed previously andthereafter the delivery unit is inserted therein and joined thereto, apair of gusset portions 4 are located on one side 3a of the two flatportions 3a, 3b near the upper opening of the container body as shown inFIG. 12. Therefore, it is easy to handle the delivery unit and thecontainer body during manufacturing the liquid container.

As shown in FIG. 11, it is preferable that the seal portion 30 of thetemporary bonding has a triangle recess at the center portion on oneside thereof, and each edge 31 of the recess crosses obliquely over eachfolding line of the inward end portions 15 of the films for the gussetportions so that the sealing area of the seal portion 30 is enlargedtoward the direction of the side portion of the container body. When theseal portion of the temporary bonding is formed into the above shapehaving the recess, the strength of the top seal lines of the containerbody against the various impacts, such as an impact when the containerdrops down, is increased, and thus the breakage at the top seal lines ofthe container is remarkably reduced.

After the temporary bonding, the periphery of the superposed films issealed to form the container body which opens at the upper end thereof.Subsequently, the conduit portion of the delivery unit is inserted intothe inside of the container body through the upper opening thereof andpositioned therein in a state that the flange portion of the deliveryunit is set at the upper end portion of the container body so as to beoverlapped with both inward end portions of the pair of films for thegusset portions. Then, the end portion of the upper opening of thecontainer body and the flange portion of the delivery unit are sealedtogether to complete the liquid container.

As to the above process, the order of respective steps can be optionallychanged, as long as two films for the gusset portions are temporarilybonded before the positioning of the delivery unit. For example, in theabove case, the delivery unit is disposed in the container body afterformation of the container body. However, the following operation may beconducted. That is, at first, the two films for gusset portions arepositioned on one film for the flat portion to be temporarily bondedthereto, and secondly the delivery unit and another film for the flatportion are positioned thereon, and finally the whole periphery of thefilms is sealed.

As shown in FIG. 2, thus obtained liquid container has an excellentstability in self-standing when it is displayed or put on the shelf,because the width W1 of each gusset portion is made approximately equalto that W2 of each flat portion so that the sectional view of thecontainer body has an approximately regularly square shape. Therefore,the liquid container according to the present invention is utilized asthe container for the beverages, needless to say, also utilized forvarious things such as the seasonings, the sauces and so forth insteadof the glass bottles and plastic containers.

Furthermore, when the sectional view of the container body isapproximately regularly square, the liquid container not only has theexcellent stability in self-standing but also can ensures a large innerspace to store the content while reducing the surface area of thecontainer body. Therefore, the liquid container according to the presentinvention has no bulky shape irrespective of its relatively largevolume.

What is claimed is:
 1. A liquid container comprising:a bag-shapedcontainer body formed of a flexible film and composed of two flatportions which constitute front and back walls and two gusset portionswhich are folded inwardly and constitute side walls of the container;and a pipe-shaped delivery unit having at least a mouth portion which isformed at an upper end thereof and projects out of an upper end portionof the container body, and a flange portion which is formed below saidmouth portion and held at the upper end portion of the container body toconstitute a joining portion between the delivery unit and the containerbody, wherein, each of said gusset portions has a width approximatelyequal to that of each flat portion, inward end portions of the twogusset portions which are projected inwardly of the container body beinginterposed between the flange portion and the flat portions at thejoining portion.
 2. A liquid container according to claim 1, whereinsaid delivery unit further has a conduit portion which is formed belowthe flange portion and extends inwardly of the container body.
 3. Aliquid container according to claim 1, wherein both of said inward endportions of the two gusset portions are disposed on the same side of theflange portion.
 4. A liquid container according to claim 1, wherein saidcontainer body is sealed at each of four corner portions of a bottomportion thereof along each of four oblique seal lines, which extendsfrom a side edge of the flat portion to a bottom edge thereof and passesthrough a position where a folding line of the gusset portion and abottom seal line of the container body cross each other, and is cut offin a trapezoidal shape at an outside portions beyond each of obliqueseal line and the bottom seals line.
 5. A liquid container according toclaim 1, wherein said container body is sealed at the upper end portionthereof along top seal lines which extend from the joining portionoutwardly and have a width larger than that of a seal line forming thejoining portion, an edge line of each transitive portion between a lowercorner of the joining portion and a lower edge of the top seal lineextending substantially parallel to an axis of the container body.
 6. Aliquid container according to claim 1, wherein said flexible film is acomposite film composed by laminating a polyester film to be anoutermost layer, a film having a barrier property, a film selected froma group consisting of polyester films or oriented nylon films, and apolyethylene film to be an innermost layer in this order.